Work will be continued principally on the following projects: Macrolide Antibiotics: We intend to continue our approach to Erythronolide, in which three segments of known stereochemistry are joined together. Similarly, our work on the synthesis of histrionicotoxin in which we are concentrating on the synthesis of the highly unsaturated members of this class and, finally, on the further synthetic efforts toward a rational and versatile synthesis of the tetracycline antibiotics, in particular with respect to solving the problem of oxygen introduction at position 12a, and of the cis A:B stereochemistry.